THE still night air over Crater City was shattered by the sound of bagpipes as pipe major Kenneth Robson struck up with Monymusk – the regimental charge of the Argyll & Sutherland Highlanders.

It was 7pm on July 3, 1967, and the 700 men of the 1st Battalion Argyll & Sutherland Highlanders were on the edge of the city, tensely awaiting the order to advance.

Two weeks before, on June 20, the Army had experienced one of its bloodiest days since World War II, when 22 soldiers – three of them Argylls – were massacred by rogue elements of the local Arab police, who now controlled Crater, a city built on an extinct volcano in the heart of the British colony of Aden in the Middle East.

After the attack, the senior British commanders in Aden had ordered the Army to withdraw from Crater, leaving the city in the hands of the police mutineers.

But one man was determined to end the stand-off and bring Crater back under British control – the commander of the Argyll & Sutherland Highlanders, Colonel Colin Mitchell. He was a pugnacious, outspoken maverick who after that night’s events, would forever be known as Mad Mitch.

Historian Aaron Edwards, who has written a new biography of Mitchell, said: “The plan he was about to set in motion represented the culmination of a personal commitment to wreak vengeance on those he held responsible for the events of June 20.”

Born in 1925, Colin Campbell Mitchell joined the Argyll & Sutherland Highlanders in 1943 and saw action in Italy in the last weeks of the war. He went on to serve in Palestine – where he was almost killed in the bombing of the King David Hotel by the Jewish Irgun insurgent group in 1946 – Korea, Cyprus and Borneo.

At the beginning of 1967, by now a Lieutenant-Colonel, he was given command of the 1st Battalion the Argyll & Sutherland Highlanders, and in June was sent to Aden – a British colony due to be granted independence by the year’s end.

But the Argylls’ arrival coincided with a mutiny by the Aden police, infiltrated by National Liberation Front terrorists, who turned their guns on the Brits, murdering 22 soldiers, including three from Mitchell’s battalion, and seizing control of Aden’s Crater district.

To Mitchell’s fury, the military commanders in Aden refused to order his men to retake Crater, fearing it would result in heavy casualties.

Mitchell later described his battalion standing down as “the most astonishing and, to my mind, disgraceful act by the higher command”.

With terrorists openly controlling Crater and Press criticism of British inaction mounting, two weeks later, Middle East Command reluctantly gave Mitchell permission to make a “limited probe” into the city.

On the night of July 3, 1967, in operation Stirling Castle, Mitchell led his men back into Crater and retook the entire city with only a few shots fired. Overnight, he became a national hero, with the Press christening him Mad Mitch for his bold actions.

But, behind the scenes, there were growing tensions between Mitchell and his superior officers, Brigadier Dunbar and General Towers.

“What annoyed Dunbar was Colin’s insistence on briefing the Press about his intentions before he had even spoken to higher command,” said Aaron. “In courting the media in such an explicit way, while acting irreverently about his superior officers, he risked his career.”

Matters came to a head on July 22 when he was summoned for a reprimand by the Commander-in-Chief of Middle East Command, Admiral Michael Le Fanu, and threatened with dismissal.

“I was not invited to say anything by way of explanation or to defend myself in any way,” Mitchell later recorded.

However, Le Fanu stopped short of relieving him of his command, fearing the damage it would do to the morale of his battalion.

But controversy continued to surround Mitchell throughout his time in Aden, with local Arabs and officials at the British High Commission in the colony accusing his men of using excessive force to maintain order.

Mitchell strenuously denied that and suspected fellow officers, jealous of the media attention the Argylls were receiving, of orchestrating a smear campaign against him and his men.

Disillusioned by his treatment from his superiors and passed over for promotion upon his return from Aden, Mitchell resigned from the British Army in July 1968.

But after stints as a war correspondent, Tory MP for West Aberdeenshire and defence consultant, Mitchell underwent a remarkable transformation from Empire warrior to crusading humanitarian. The catalyst was a clandestine visit to war-torn Afghanistan on a fact-finding mission in the early 80s, the height of the Soviet occupation, during which countless landmines were scattered throughout the country, maiming thousands of civilians.

“In 1983, he walked more than 100 miles from Afghanistan to Quetta and Peshawar in Pakistan to personally see at close quarters the full extent of the horrors inflicted on the people of these war-torn regions,” Aaron added.

Appalled by what he witnessed, Mitchell resolved to tackle the scourge of landmines and in 1988, he founded the HALO Trust with his wife Sue and fellow ex-Army officer Guy Willoughby. It was the world’s first charity dedicated to mine clearance in former war zones.

“I thought their eyes would mist over with tears or laughter,” Mitchell later admitted. “But in fact, both accepted that it was quite a good concept.”

Working out of a converted stable block in Dumfries, HALO (Hazardous Areas Life-Support Organisation) have become the world’s foremost “demining” organisation, destroying more than 1.4million landmines and clearing 82,000 acres of land of unexploded ordnance, from Central America to Africa, the Balkans to Asia.

After Mitchell’s death in 1996, at age 70, his son Angus said: “He was always a maverick. In his final years, he chose the dirtiest and most dangerous job left on Earth – clearing up the lethal debris of war. It became an obsession with him.”

Aaron said: “As a counterweight to his earlier Mad Mitch persona, or perhaps in spite of it, he shunned the glitz and glamour. In Guy’s words, ‘Mitch virtually invented the whole business and he had one rule – no (Press) conferences, no PR razzmatazz. Just action’.”

But even in his new role, Mitchell’s outspoken nature occasionally reasserted itself.

In 1991, he publicly lambasted the Overseas Development Administration for what he saw as a lack of support for HALO’s demining operation in Cambodia.

He fumed: “They’re bureaucrats. They don’t seem to understand that 250 people a month are being injured by these mines.”

Even all those years after Aden, British officialdom was still making Mitch mad.

*Mad Mitch’s Tribal Law: Aden & the End of Empire by Aaron Edwards is out now, Mainstream Publishing, £19.99.